Bread comprising saccharified rice solution and method for preparing same

ABSTRACT

The present invention relates to a bread comprising a saccharified rice solution and a method for preparing same and, more specifically, to a bread comprising a saccharified rice solution prepared by using  Aspergillus oryzae  koji,  Aspergillus kawachii  koji, and lees and a method for preparing same. According to the present invention, a saccharified rice solution prepared by using  Aspergillus oryzae  koji,  Aspergillus kawachii  koji, and lees is developed, and thus, as compared with an existing saccharified rice solution prepared by using  Aspergillus oryzae  koji or  Aspergillus kawachii  koji, sweetness may be reduced, and the amounts of glutamic acid and aspartic acid may be increased, thus giving further enhanced savory taste. Furthermore, various and rich flavors (aroma) may be enhanced. In addition, by addition of the saccharified rice solution of the present invention, a bread having savory taste and various and rich flavors (aroma) may be prepared.

TECHNICAL FIELD

The present invention relates to bread containing a saccharified rice solution and a method for preparing the same and more specifically, to bread containing a saccharified rice solution prepared using Aspergillus oryzae koji, Aspergillus kawachii koji and lees, and a method for preparing the same.

BACKGROUND ART

In general, bread refers to a product by fermenting a mixture of wheat flour as a main ingredient with water, and then baking the resulting product in an oven. Flour, salt, water, yeast, and dairy products are blended to prepare a dough. In this case, nuts or dried fruits are also added thereto. The quality of bread may depend on the ratio of ingredients and the preparation process. The fermentation process is very important in order to produce high-quality bread and greatly affects the physical properties and flavor of the bread.

Recently, research has been conducted on baking using saccharified rice. In the prior art, Korean Patent No. 10-1750154 discloses a rice fermented composition and rice bread having superior effect of aging-retardation and a method of preparing the same, and Korean Patent No. 10-1926741 entitled “natural fermented bread using rice” discloses a method of improving the quality of bread using fermented rice broth. Therefore, the present invention discloses a method of preparing a saccharified rice solution having improved taste and flavor while solving the problems of conventional saccharified rice solutions, and a method of producing bread containing the same.

DISCLOSURE Technical Problem

Conventionally, a saccharified rice solution has been prepared using Aspergillus oryzae koji or Aspergillus kawachii koji. In this case, the sweetness increases depending on saccharification. However, there is a recent trend in which consumers are averse to sweet flavors. Therefore, the present invention aims at preparing a saccharified rice solution that has improved various and rich flavors including umami and reduced sweetness compared to a conventional saccharified rice solution prepared using Aspergillus oryzae koji or Aspergillus kawachii koji, and developing bread with improved various and rich flavors including umami, containing the saccharified rice solution.

Technical Solution

In accordance with one aspect of the present invention, the above and other objects can be accomplished by the provision of a saccharified rice solution prepared by adding Aspergillus oryzae koji, Aspergillus kawachii koji and lees to rice flour or rice, followed by hydrolysis.

Meanwhile, the rice flour is preferably alpha rice flour.

Meanwhile, the saccharified rice solution is preferably prepared by further adding glucose or rice syrup to the rice flour or rice, followed by hydrolysis.

In accordance with another aspect of the present invention, provided is a flour dough for baking containing the saccharified rice solution.

In accordance with another aspect of the present invention, provided is bread prepared by baking the dough.

Advantageous Effects

The present invention provides a saccharified rice solution that is prepared using Aspergillus oryzae koji, Aspergillus kawachii koji and lees, and thus is capable of reducing sweetness, providing a further enhanced umami taste based on increased contents of glutamic acid and aspartic acid, and improving various and rich flavors (aroma) compared to a conventional saccharified rice solution prepared using Aspergillus oryzae koji or Aspergillus kawachii koji.

DESCRIPTION OF DRAWINGS

FIG. 1 is a graph showing the results of analysis of the physical properties of bread produced using the saccharified rice solution of the present invention.

FIG. 2 is a graph showing the results of analysis of aroma components of bread produced using the saccharified rice solution of the present invention.

BEST MODE

Conventionally, a saccharified rice solution has been prepared using Aspergillus oryzae koji or Aspergillus kawachii koji. In this case, the sweetness increases due to saccharification. However, there is a recent trend in which consumers are averse to sweet flavors. Therefore, the present inventors made extensive efforts to develop a saccharified rice solution that reduces sweetness and improves various and rich flavors including umami, while maintaining the advantages of conventional saccharified rice solutions prepared using Aspergillus oryzae koji or Aspergillus kawachii koji.

The present invention provides a saccharified rice solution prepared by hydrolyzing rice flour or rice to which Aspergillus oryzae koji, Aspergillus kawachii koji and lees have been added.

In the present invention, an optimum process of preparing a saccharified rice solution having a high sensory score was established by mixing Aspergillus oryzae koji with Aspergillus kawachii koji at an optimum ratio of 2.5 to 3.5:6.5 to 7.5, further adding lees thereto and performing efficient starch pre-treatment and sugar supplementation (treatment with glucose and rice syrup). At this time, more preferably, Aspergillus oryzae koji is mixed with Aspergillus kawachii koji at a ratio of 3:7. As described above, the saccharified rice solution prepared using Aspergillus oryzae koji, Aspergillus kawachii koji and lees is capable of reducing sweetness to an appropriate level and improving various and rich flavors (fragrance) including umami compared to a saccharified rice solution prepared using only Aspergillus oryzae koji, or Aspergillus kawachii koji.

In addition, the contents of aspartic acid and glutamic acid showing the umami in the saccharified solution containing only Aspergillus oryzae koji or Aspergillus kawachii koji are 0.016% and 0.033%, respectively, but the contents of aspartic acid and glutamic acid in the saccharified solution containing Aspergillus oryzae koji, Aspergillus kawachii koji and lees are 0.023% and 0.049%, which correspond to 69.5% and 67.3% increases, respectively. As described above, the saccharified rice solution prepared using Aspergillus oryzae koji, Aspergillus kawachii koji and lees according to the present invention exhibits remarkably improved umami compared to a saccharified rice solution prepared using only Aspergillus oryzae koji, or Aspergillus kawachii koji.

Meanwhile, any rice flour may be used as the rice flour without limitation as long as it is known in the art, but the rice flour is preferably alpha rice flour. The alpha rice flour means alpha (α)-starch rice flour (i.e., rice flour gelatinized into alpha-starch).

Meanwhile, in the present invention, the saccharified rice liquid is preferably prepared by hydrolyzing rice flour or rice to which glucose or rice syrup has been further added.

The Aspergillus oryzae koji derived from Aspergillus oryzae and the Aspergillus kawachii koji derived from Aspergillus kawachii were used.

The term “lees” refers to the residue left behind after the liquor ingredient is filtered from raw rice wine or sake (unfiltered liquor), which is also called “sake lees”. Lees contain large amounts of dietary fibers, proteins, amino acids, organic acids and vitamins, as well as enzymes such as amylase and protease. Here, saccharification of Rhizopus oryzae left over lees was used.

Meanwhile, the present invention provides a flour dough for baking containing the saccharified rice solution.

Meanwhile, the flour dough for baking is preferably obtained by performing primary fermentation using strong flour, water, and yeast Saccharomyces cerevisiae SPC-SNU 70-1 (KCTC 12776BP) to prepare a sponge dough, adding the saccharified rice solution of the present invention to the sponge dough and then performing secondary fermentation on the resulting mixture.

Meanwhile, in the present invention, the sponge dough may be prepared under any fermentation conditions that allow yeast strains to grow. Preferably, the dough is mixed at a temperature of 24 to 26° C., is allowed to stand at 22 to 28° C. for 20 to 40 minutes, and is fermented at a low temperature of 4 to 8° C. for 14 to 18 hours. The fermentation at a low temperature for a long time as in the above conditions has advantages of causing accumulation of metabolites and increasing extensibility and flavors of the product. In addition, such a method has a low production risk and high efficiency compared to a straight method.

Meanwhile, in the process of preparing the dough of the present invention, the fermentation is preferably performed such that the dough is mixed at a temperature of 26 to 28° C., intermediate fermentation is performed at a temperature of 25 to 28° C. and a relative humidity of 80 to 90% for 20 to 40 minutes, rounding is performed and aging is performed at a temperature of 25 to 28° C. and a relative humidity of 80 to 90% for 10 to 20 minutes. Through the above process, gluten is rearranged and stabilized to prepare for fermentation.

Also, the present invention provides bread prepared by baking the dough.

Also, the present invention provides bread prepared by baking the dough.

Any dough may be used as the dough for baking as long as it is generally prepared by adding water and the like to wheat flour, and if necessary, by adding salt (preferably refined salt), refined sugar, shortening, or the like thereto.

The term “baking” used herein generally means a process of baking to produce bread, and specifically refers to a method of baking using dry heat in an oven. Since a known conventional method can be used, a detailed description thereof will be omitted.

As can be seen from the following example, the present invention provides a saccharified rice solution that is prepared using an Aspergillus oryzae koji, an Aspergillus kawachii koji, and lees and thus is capable of reducing sweetness and improving various and rich flavors (fragrance) including umami taste, compared to a conventional saccharified rice solution prepared using Aspergillus oryzae koji or Aspergillus kawachii koji. Also, bread having excellent various and rich flavors (fragrance) including umami taste can be produced using the saccharified rice solution.

Hereinafter, the present invention will be described in more detail with reference to the following examples. The scope of the present invention is not limited to the examples, and encompasses modifications of the technical concept equivalent thereto.

Example 1: Preparation of Saccharified Rice Solution Using Aspergillus oryzae Koji and Aspergillus kawachii Koji of Present Invention

In this example, an optimal process for preparing a saccharified rice solution having excellent sensory scores was established by setting an optimal mixing ratio of Aspergillus oryzae koji to Aspergillus kawachii koji and then further performing efficient starch pre-treatment and sugar supplementation (treatment with glucose and rice syrup).

1) Analysis Method

For analysis of the saccharified rice solution, pH, TTA (measurement of acidity), Brix (measurement of sweetness), organic acid, free sugar, and free amino acid were analyzed and sensory evaluation was performed.

Specifically, pH analysis was performed by homogenizing a mixture of 5 g of a sample with 95 mL of distilled water and then measuring the pH of the resulting sample three times using a pH meter. For TTA analysis, the appropriate amount of NaOH was measured in accordance with 6.8.1.1 Acidity, 6. the Food Standards Test Method, 8. General Test Method, in Food Codex. For Brix analysis, the refractive index of the saccharometer was measured in accordance with 2.1.4.1 saccharide, 2. Food Ingredients Test Method, 8. General Test Method in Food Codex. For sensory evaluation, properties, taste, texture, and color were evaluated in accordance with 1.1 Property (sensory evaluation), 1. Food General Test Method, 8. General Test Method in Food Codex.

In addition, the organic acids, free sugars, and free amino acids were assayed by instrumental analysis, and detailed analysis conditions are shown in Tables 1 to 3.

TABLE 1 Organic acid assay Analytical UPLC (Waters, USA) Model name: Acquity UPLC Instrument Column Unison US-C18 (Imtakt, USA) 250 × 4.6 mm, 5 μm Detector PDA (Waters, USA) Analysis Mobile Phase: 0.1% phosphoric acid conditions Flow rate: 0.7 ml/min Column Temperature: 25° C. Sample Temperature: 20° C. Sample 2 g of sample is diluted 10x with tertiary DW (w/w %), preparation followed by mixing under vortexing. After centrifugation, the supernatant is diluted at a suitable ratio for analysis (final dilution ratio of 1/20), and then filtered through 0.45 μm filter. Instrumental analysis

TABLE 2 Free sugar analysis Analytical HPLC (Shiseido, USA) Model name: Nanospace S1-2 Instrument Column Carbohydrate High Performance (Waters) 4.6 × 450 mm, 4 μm Detector RID (Shiseido, USA) Analysis Mobile Phase: 80% Acetonitrile conditions Flow rate: 1 ml/min Column Temperature: 35° C. Sample 2 g of sample is diluted 10x with tertiary DW (w/w %), preparation followed by mixing (under vortexing, product (bread): Sonication 5 min) After centrifugation, the supernatant is diluted at a suitable ratio for analysis and then filtered through 0.45 μm filter, (final dilution ratio: material 1/100, product (bread) 1/10) Instrumental analysis

TABLE 3 Free amino acid assay Analytical HPLC (Thremo Dionex, USA) Model name: Dionex Ultimate Instrument 3000 Column Inno Cl8 column (YoungJin Biochrom, Korea) 4.6 × 450 mm, 5 μm Detector FL Detector (Agilent, USA) Analysis Mobile Phase A: 40 mM Sodium phosphate, pH 7 conditions Mobile Phase B: 3DW/Acetonitrile/Methanol (10:45:45 v/v %) Flow rate: 1.5 ml/min Column Temperature: 40° C. Sample Temperature: 20° C. Sample 2 g of sample is diluted 10x with tertiary DW (w/w %), preparation followed by mixing under vortexing After centrifugation, the supernatant is diluted at a suitable ratio for analysis and then filtered through 0.45 μm filter. Instrumental analysis

2) Setting Optimal Mixing Ratio of Saccharified Rice Solution Using Aspergillus oryzae Koji and Aspergillus kawachii Koji

In the present invention, a saccharified rice solution exhibiting excellent sensory properties was prepared using Aspergillus oryzae koji and Aspergillus kawachii koji, instead of malt, which is generally used as an enzyme source. During the saccharification process, Aspergillus oryzae formed in Aspergillus oryzae koji, produces saccharides, decomposes rice proteins to produce amino acids, and creates a mild sweetness. In addition, Aspergillus kawachii formed in Aspergillus kawachii koji produces various organic acids, especially fresh acidic flavor (citric acid). Based thereon, Aspergillus kawachii can create a variety of tastes (sour taste and umami taste) than conventional saccharified liquids (e.g., Sikhye (Korean traditional rice beverage).

Meanwhile, in the present invention, it was attempted to set the optimal mixing ratio of Aspergillus oryzae koji to Aspergillus kawachii koji. For this purpose, saccharified rice solutions were prepared by varying the mixing ratio of Aspergillus oryzae koji to Aspergillus kawachii koji, the pH, TTA, Brix, total organic acid content, total free sugar content, and total free amino acid content of the saccharified rice solutions were measured and sensory evaluation was performed. The results are shown in Table 4. In addition, the results for detailed components of metabolites, organic acids, free sugars, and free amino acids are shown in Table 5. Based thereon, it was possible to calculate the optimal mixing ratio (2.5-3.5:6.5-7.5) of Aspergillus oryzae koji to Aspergillus kawachii koji, which had the best sensory score.

TABLE 4 TI T2 T3 T4 T5 Hard rice 21.74 21.74 21.74 21.74 21.74 Aspergillus 10.87 15.22 21.74 0 6.52 oryzae koji Aspergillus 10.87 6.52 0 21.74 15.22 kawachii koji Feed water 56.52 56.52 56.52 56.52 56.52 Total 100 100 100 100 100 Remarks Aspergillus Aspergillus Aspergillus Aspergillus Aspergillus oryzae oryzae oryzae kawachii oryzae koji:Aspergillus koji:Aspergillus koji koji koji:Aspergillus kawachii kawachii 100% 100% kawachii koji = 5:5 koji = 7:3 koji = 3:7 Brix 43.3 43.4 45.3 42.8 42.1 (Sweetness measurement) pH 4.47 4.79 5.94 3.92 4.18 TTA 5.98/12.29 4.03/10.02 1.07/5.73 12.14/19.38 8.35/14.82 (Acidity measurement) Total organic acid 0.217 0.156 0.033 0.300 0.273 (%) Total free sugar 30.328 30.244 32.482 28.795 26.891 (%) Total free amino 0.378 0.414 0.395 0.338 0.371 acid (%) Sensory score 5.84 5.59 3.41 4.52 7.21 (9-point scale)

TABLE 5 Analysis items Tl T2 T3 T4 T5 Organic Malic acid 0.063 0.058 0.024 0.041 0.021 acid Lactic acid 0.021 0.006 0.000 0.099 0.067 (%) Acetic acid 0.000 0.000 0.000 0.000 0.000 Citric acid 0.000 0.000 0.000 0.000 0.000 Succinic acid 0.124 0.084 0.000 0.152 0.186 Fumaric acid 0.009 0.009 0.009 0.008 0.000 Total 0.217 0.156 0.033 0.300 0.273 Free sugar Fructose 0.000 0.000 0.000 0.000 0.000 (%) Glucose 23.369 25.381 27.353 23.951 22.528 Sucrose 0.000 0.000 0.000 0.000 0.000 Maltose 6.959 4.862 5.129 4.844 4.363 Lactose 0.000 0.000 0.000 0.000 0.000 Total 30.328 30.244 32.482 28.795 26.891 Free Aspartic acid 0.017 0.019 0.027 0.014 0.016 amino acid Glutamic acid 0.036 0.041 0.047 0.028 0.033 (%) Asparagine 0.019 0.019 0.014 0.015 0.017 Serine 0.015 0.018 0.025 0.009 0.013 Glutamine 0.028 0.033 0.028 0.016 0.022 Histidine 0.011 0.010 0.007 0.009 0.010 Glycine 0.009 0.011 0.015 0.005 0.007 Threonine 0.011 0.015 0.019 0.006 0.009 Arginine 0.002 0.001 0.001 0.062 0.038 Alanine 0.024 0.028 0.032 0.017 0.021 GABA 0.002 0.003 0.005 0.002 0.002 Tyrosine 0.028 0.030 0.024 0.024 0.026 Valine 0.022 0.026 0.027 0.011 0.018 Methionine 0.011 0.012 0.011 0.009 0.010 Ornithine 0.000 0.000 0.000 0.000 0.000 Tryptophan 0.008 0.009 0.008 0.008 0.009 Phenylalanine 0.030 0.032 0.016 0.026 0.028 Isoleucine 0.015 0.019 0.020 0.007 0.011 Leucine 0.048 0.050 0.039 0.041 0.045 Lysine 0.025 0.023 0.014 0.020 0.024 Proline 0.017 0.016 0.017 0.019 0.014 Total 0.378 0.414 0.395 0.338 0.371

3) Preparation of Saccharified Rice Solution at Optimum Mixing Ratio of Aspergillus oryzae Koji to Aspergillus kawachii Koji Using Addition of Sugar Supplementation

The sugar content in the saccharified rice solution prepared at the optimal mixing ratio of Aspergillus oryzae koji to Aspergillus kawachii koji (2.5˜3.5:6.5˜7.5) was corrected and sugar supplementation was performed to prevent quality deviation. In order to confirm the optimal sugar supplementation, pH, TTA, Brix and total free sugar content of the saccharified rice solution prepared by changing the mixing ratio of supplemented sugar components (glucose, sugar, rice syrup) were measured and sensory evaluation was performed. The results were as shown in Table 6, which shows that the experimental group supplemented with glucose and rice syrup had the best sensory score as the harmony of sweetness was the best.

TABLE 6 T6 T7 T8 T9 T10 T11 Hard rice 21.74 21.74 21.74 21.74 21.74 21.74 Aspergillus 6.52 6.52 6.52 6.52 6.52 6.52 oryzae koji Aspergillus 15.22 15.22 15.22 15.22 15.22 15.22 kawachii koji Feed water 56.52 56.52 56.52 56.52 56.52 56.52 Total 100 100 100 100 100 100 Glucose 25 0 0 12.5 0 12.5 Rice syrup 0 25 0 0 12.5 12.5 Sugar 0 0 25 12.5 12.5 0 Remarks Glucose Rice syrup Sugar Glucose, Sugar, rice Glucose, sugar syrup rice syrup Brix 41.6 40.3 43.9 43.2 42.1 42.1 pH 4.04 4.07 4.02 4.04 4.01 4.18 TTA 6.44/11.13 6.71/12.02 6.57/11.31 6.33/11.01 7.13/12.50 8.35/14.82 (Acidity measurement) Total free sugar 31.850 22.790 31.110 31.090 27.030 26.891 (%) Sensory score 5.25 5.09 5.46 6.84 6.45 7.14 (9-point scale)

4) Preparation of Saccharified Rice Solution Prepared at Optimum Mixing Ratio of Aspergillus oryzae Koji to Aspergillus kawachii Koji, while Performing Sugar Supplementation and Varying Starch Pre-Treatment Process

A saccharified rice solution was prepared at the optimal mixing ratio of Aspergillus oryzae koji to Aspergillus kawachii koji (2.5˜3.5:6.5˜7.5), while performing sugar supplementation and changing starch pre-treatment (gelatinization, a-starch). The pH, TTA, Brix and total free sugar content of the saccharified rice solution were measured and sensory evaluation thereof was performed. The moisture content of hard rice prepared by the gelatinization process was calculated, the content of alpha rice flour (rice flour) prepared by the a-starch preparation process was reduced, and the feed water content was increased to adjust the content of the starch used for saccharification to a similar level thereto. The results of total organic acids, total free sugars, total free amino acids and sensory scores after starch pretreatment (gelatinization, a-starch) were overall similar (Table 7). Therefore, it is possible to use alpha rice flour (rice flour) instead of hard rice in the preparation process. Based thereon, it is possible to shorten the process of preparing hard rice and pulverize raw materials and thereby to improve shelf life and production workability.

TABLE 7 T12 T13 Hard rice 21.74 0 Aspergillus 6.52 6.25 oryzae koji Aspergillus 15.22 14.58 kawachii koji Feed water 56.52 64.58 Alpha rice flour 0 14.58 (Rice flour) Total 100 100 Glucose 12.5 12.5 Rice syrup 12.5 12.5 Total 125 125 Brix 42.1 41.9 pH 4.18 4.31 TTA 8.35/14.82 8.16/14.97 (acidity measurement) Total organic acid 0.273 0.316 (%) Total free sugar 26.891 25.881 (%) Total free amino 0.371 0.378 acid (%) Sensory score 7.21 7.29 (9-point scale)

Example 2: Preparation of Saccharified Rice Solution Using Aspergillus oryzae Koji, Aspergillus kawachii Koji and Lees of Present Invention

In this example, a saccharified rice solution was prepared by adding lees in order to supplement the saccharified rice solution using Aspergillus oryzae koji or Aspergillus kawachii koji in Example 1. In the saccharification process of Rhizopus oryzae remaining in lees, starch is decomposed to produce free sugars and amino acids.

The pH, TTA, Brix, total organic acid content, total free sugar content, and total free amino acid content of the saccharified rice solution prepared by varying the amount of lees while Aspergillus oryzae koji and Aspergillus kawachii koji are used at the optimal mixing ratio were measured and sensory evaluation was performed. The results are shown in Table 8. In particular, as the alpha rice flour content of the starch material increases, the metabolite content and the sensory evaluation score increase. Therefore, among the saccharified rice solutions to which lees were added, T15 was set as the optimal experimental group.

TABLE 8 T14 T15 T16 T17 Aspergillus 2.65 2.29 2.65 2.39 oryzae koji Aspergillus 6.35 5.72 6.35 5.74 kawachii koji Feed water 31.75 29.85 42.33 33.49 Lees 52.91 45.72 42.33 52.63 Alpha rice flour 6.35 16.43 6.35 5.74 (rice flour) Total 100 100 100 100 Glucose 5.3 5.1 5.3 5.3 Rice syrup 5.3 5.1 5.3 5.3 Total 110.58 110.58 110.58 110.58 Brix 27.7 34.9 26.7 27 (Sweetness measurement) pH 4.42 4.27 4.16 4.14 TTA 7.46/13.40 9.11/14.10 7.34/13.10 8.33/13.86 (Acidity measurement) Total organic acid 0.3231 0.218 0.280 0.309 (%) Total free sugar 14.859 16.390 15.641 13.797 (%) Total free amino 0.394 0.379 0.399 0.391 acid (%) Sensory score 4.86 6.72 5.18 5.54 (9-point scale) Remarks Low alpha Low lees High lees rice flour content content content

Meanwhile, in order to perform sensory evaluation upon addition of lees, the contents of ingredients of free amino acids were further analyzed. As a result, as shown in Table 9, the contents of glutamic acid and aspartic acid, which are amino acids related to umami, in T15 (saccharified rice solution containing lees, Table 8) compared to T5 (saccharified rice solution without lees, Table 4) were high, and the contents of proline, ornithine, and leucine, which were used to create a strong flavor felt in the bread crust, were high. This indicates that the umami taste and flavor are enhanced by the addition of lees.

TABLE 9 Analysis items T5 T15 Free Aspartic acid 0.016 0.023 amino acid Glutamic acid 0.033 0.049 (%) Asparagine 0.017 0.023 Serine 0.013 0.019 Glutamine 0.022 0.027 Histidine 0.010 0.014 Glycine 0.007 0.018 Threonine 0.009 0.014 Arginine 0.038 0.073 Alanine 0.021 0.042 GABA 0.002 0.003 Tyrosine 0.026 0.030 Valine 0.018 0.021 Methionine 0.010 0.011 Ornithine 0.000 0.006 Tryptophan 0.009 0.027 Phenylalanine 0.028 0.011 Isoleucine 0.011 0.000 Leucine 0.045 0.042 Lysine 0.024 0.036 Proline 0.014 0.032 Total 0.371 0.52

Overall, by addition of lees, it was possible to prepare a saccharified rice solution with enhanced various rich flavor, including umami, while appropriately reducing the sweetness created in the saccharified rice solution using Aspergillus oryzae koji or Aspergillus kawachii koji.

Example 3: Preparation of Bread Using Saccharified Rice Solutions of Examples 1 and 2 and Testing

In this example, bread (plain bread) was prepared using the saccharified rice solutions of Example 1 (containing Aspergillus oryzae koji and Aspergillus kawachii koji) and Example 2 (containing Aspergillus oryzae koji, Aspergillus kawachii koji and lees) and tested.

1) Preparation of Bread (Plain Bread) Using Saccharified Rice Solutions of Examples 1 and 2

The components of the sponge dough (see Table 10 below) were put into a mixer (product name: SK101S MIXER: Japan), kneaded in the second stage for 2 minutes and in the third stage for 1 minute, and mixed such that the final temperature of the dough was 25° C. Then, the dough was allowed to stand at room temperature for 30 minutes, and then primarily fermented in a fermenter at 6° C. for 16 hours to prepare sponge dough. Then, the components of the dough (see Table 10 below) are put into a mixer (product name: SK101S MIXER: Japan), kneaded in the first stage for 1 minute, the sponge dough was added thereto, and the resulting mixture was kneaded in the second stage for 3 minutes and in the third stage for 3 minutes, and mixed such that the final temperature of the dough was 27° C. The dough was intermediate-fermented in a fermenter at 27° C. and a relative humidity of 85% for 30 minutes, was divided into uniform segments, rounded, and aged in a fermenter at 27° C. and a relative humidity of 85% for 15 minutes. After aging, the dough was molded and placed in a bread case. Then, the dough placed in the bread case was fermented at 37° C. and at a relative humidity of 85% for 50 minutes to prepare bread dough. The prepared bread dough was baked in an oven at an upper heat of 170° C. and at a lower heat of 210° C. for 35 minutes, and then was cooled at room temperature until the internal temperature reached 32° C.

TABLE 10 Addition of Addition of Example 1 Example 2 Control saccharified saccharified group rice solution rice solution Sponge Strong flour 70 70 70 dough Commercial yeast: 0.7 0.7 0.7 Saccharomyces cerevisiae (SPC- SNU 70-1 (KCTC 12776BP)^(a) Rimusoft^(b) 0.3 0.3 0.3 Feed water 42 42 42 Dough Strong flour 3 30 30 Refined salt 1.8 1.8 1.8 White sugar 7 7 7 Whole milk powder 3 3 3 Butter 10 10 10 Commercial yeast 0.6 0.6 0.6 Feed water 13 7 8 Example 1 0 10 0 saccharified rice solution (T13) Example 2 0 0 10 saccharified rice solution (T15)

a: Saccharomyces cerevisiae SPC-SNU 70-1 (KCTC 12776BP) is derived from Korean Patent No. 10-1551839 (Registration date: Sep. 3, 2015) b: Rimusoft is an emulsifier as a food additive (glycerin fatty acid ester) and represents “Rimusoft super (v)”.

2) Texture and Ingredient Analysis and Sensory Evaluation of Bread

The texture and component analysis, and sensory evaluation of bread prepared using the saccharified rice solutions of Examples 1 and 2 above were performed.

First, the texture (physical property) was compared using a texture analyzer (Stable Micro Systems texture analyzer). As analysis indicators, hardness, cohesiveness, springiness, gumminess, chewiness, and resilience were measured. A higher hardness value indicates higher hardness. Springiness means the degree to which a substance returns to its original state, cohesiveness means the ability of food to retain its original state, gumminess means stickiness, chewiness refers to the degree of swallowing, and resilience refers to a force at which an object is restored after pressed. Each analysis parameter was repeatedly measured in 3 replicates.

As a result, as can be seen from FIG. 1 and Table 11, both bread produced using the saccharified solutions of Examples 1 and 2 had improved overall texture (decreased hardness, increased cohesiveness and resilience, and maintained springiness).

TABLE 11 Hardness Springiness Cohesiveness Gumminess Chewiness Resilience Control group 1.336 0.863 0.489 0.654 0.564 0.181 Example 1 0.84 0.746 0.513 0.712 0.349 0.194 saccharified rice solution Example 2 0.92 0.592 0.542 0.498 0.295 0.213 saccharified rice solution

Then, the free sugar component was analyzed (see Table 2), and the fragrance component was compared using the GS/MS system (Table 12).

TABLE 12 Analysis system Operation conditions GC/MS analysis *GC Model name: Agilent 7890A *Inlet temperature: 230° C. *Column: DB-WAX (60 m × 250 um × 0.25 uM) *Carrier gas: helium *Flow rate: 1 ml/min *Oven temperature program : from 40° C. (5 min) → 8° C./min → 230° C. (10 min) *MS detector: Agilent 5975C MSD (El mode) SPME analysis * Fiber: DVB/Carboxen/SPME (Supelco Co.) * Sample equilibration time incubation temp. 85° C. incubation time 30 min

As a result, as can be seen from Table 13, the bread made using the saccharified solution of Example 2 exhibited an increase in various types of sweetness (increased content of several free sugars) compared to the control group, and exhibited an appropriately reduced sweetness compared to bread made using the saccharified solution of Example 1. That is, the bread made using the saccharified solution of Example 2 had an appropriate sweetness.

TABLE 13 Example 1 Example 2 saccharified rice saccharified rice Free sugar (%) Control solution solution Fructose 0.75 1.22 1.10 Glucose 0.46 2.26 1.14 Sucrose 0.00 0.00 0.00 Maltose 2.10 2.04 1.83 Lactose 0.82 0.89 0.94 Total 4.13 6.42 5.01

Meanwhile, sensory evaluation was performed on the saccharified rice solutions of Examples 1 and 2. As a result, as can be seen from Table 14, the sensory score was higher in bread made using the saccharified solutions of Examples 1 and 2 compared to the control group, and in particular, the saccharified rice solution of Example 2 exhibited an improved umami taste compared to the saccharified rice solution of Example 1. This indicates that the umami taste and flavor are enhanced by the addition of lees.

TABLE 14 Saccharified rice Saccharified solution of rice solution of Analysis items Control Example 1 Example 2 Sensory Sweetness 4.85 8.26 6.45 evaluation Saltiness 5.16 5.03 5.71 (9-point Sourness 4.96 5.24 5.69 scale) Umami 5.48 6.33 8.17 Overall 5.11 7.21 7.94

Meanwhile, as shown in FIG. 2 and Table 15, the bread prepared using the saccharified solutions of Examples 1 and 2 were detected to have a greater variety of flavor ingredients (Example 1: 17 types, Example 2: 14 types) than the control group (12 types). Bread prepared using the saccharified rice solution of Example 1 was found to have a great amount of alcohol having fruity, floral, and whiskey flavors, and a great amount of aldehyde having savory flavors such as roasted, bread, and almond flavors. Bread made using the saccharified rice solution of Example 2 was found to have great amounts of alcohol having fruity, floral, and whiskey flavor characteristics, aldehyde having savory flavors such as roasted, bread, and almond flavors, and ester having sweet and fresh flavors such as fruity and apple flavors. This is considered to be due to various metabolites produced during the preparation of the saccharified rice solution of Example 2.

TABLE 15 Saccharified Saccharified Control rice solution rice solution Flavor Area group of Example 1 of Example 2 Description Alcohol Ethanol 38,496,132 91,670,582 160,923,927 Strong, Alcohol, Ethereal Isobutyl alcohol 6,379,861 6,427,139 9,415,984 Wine, malty 3-Methyl-1-butanol — 122,146,206 — Whiskey fruity banana 2-Heptanol 1,469,788 — — Fresh lemongrass herbal floral fruity 1-Hexanol — — 4,042,512 Green, Fruity, Sweet, Woody, Floral Phenethyl alcohol — 73,224,730 — Rose- honey-like Total 46,345,781 293,468,657 174,382,423 Aldehyde 3-Methylbutane — 1,674,724 — Chocolate, Roasted Bread, Fruity, Corn flakes Hexanal 2,813,624 2,146,948 2,120,518 Fresh, Green, Fruity, Sweaty 2-Amylfuran 2,631,942 2,355,922 2,251,848 Fruity, Green, Earthy Acetoin 2,934,085 4,467,510 3,029,328 Sweet buttery creamy dairy milky fatty Nonanal 3,296,232 1,681,528 2,714,667 Waxy, green, fatty Furfural — 3,909,770 — Sweet, Almond, Bread Benzaldehyde — 12,784,843 10,714,977 Almond, Strong, Bitter, Cherry Benzeneacetaldehyde — 3,012,631 — Honey, floral Total 1,675,883 32,033,876 20,831,338 Ketone 2-Heptanone 32,696,033 22,106,778 15,733,276 Fruity, Spicy, Sweet, Grass, Coconut, cinnamon 2-Nonanone 59,845,480 32,634,616 29,141,357 Fruity fresh sweet green weedy earthy herbal 2-Undecanone — 11,149,345 8,590,500 Floral and fatty pineapple Total 92,541,513 65,890,739 53,465,133 Ester Isoamyl formate 93,602,735 — 146,191,846 Fruity green apple Ethyl hexanoate 1,516,859 — 2,071,142 Sweet, Fruity, Green, Creamy, Milky, Balsamic Hexyl formate — 2,531,475 — Green waxy floral herbal plum apple cucumber Ethyl octanoate 14,551,853 4,392,463 — Fruity, Wine, Pear brandy, Banana, Sweet, Fresh Diethyl succinate — — 5,521,844 Fruity apple, cooked apple, ylang-ylang Total 109,671,447 6,923,938 153,784,832 Total 360,234,624 398,317,210 402,463,726

Overall, it can be seen from the above results that, using the saccharified rice solution (Example 2) containing Aspergillus oryzae koji, Aspergillus kawachii koji and lees, it is possible to prepare a saccharified rice solution that is capable of reducing sweetness and improving various and rich flavors including umami due to the high contents of glutamic acid and aspartic acid, which are umami taste-related amino acids, compared to the saccharified rice solution containing Aspergillus oryzae koji and Aspergillus kawachii (Example 1). 

1-5. (canceled)
 6. A method of preparing a saccharified rice solution comprising adding Aspergillus oryzae koji, Aspergillus kawachii koji and lees to a rice flour or rice, and conducting hydrolysis.
 7. The method according to claim 6, wherein the rice flour is alpha rice flour.
 8. The method according to claim 6, wherein the saccharified rice solution is prepared by further adding a glucose or rice syrup to the rice flour or rice prior to conducting hydrolysis.
 9. A saccharified rice solution prepared by the method of claim
 6. 10. A flour dough for baking comprising the saccharified rice solution according to claim
 9. 11. A bread prepared by baking the flour dough according to claim
 10. 